A. Field of the Invention
The present invention relates generally to the field of biology. More particularly, it concerns compounds associated with fertility and methods of use thereof.
B. Description of Related Art
Cytoplasmic droplets are remnants of spermiogenesis that often contain cytoplasm, mitochondria, and the Golgi complex. They are approximately 2 μm in size and are located on the midpiece of the spermatozoon in either the upper half or lower half of the midpiece, the proximal and distal positions, respectively. Cytoplasmic droplets (CD) are the most common abnormality associated with boar spermatozoa and it is recommended that ejaculates with more than 15% spermatozoa with CD should be discarded (Althouse, 1998).
Lipoxygenases (LOX) are enzymes that are ubiquitous in plants and animals and are member of a large family of dioxygenases (Brash, 1999; Feussner and Wasternack, 2002). The animal LOXs, mainly 5-LOX, 12-LOX, and 15-LOX, can peroxidate arachidonic acid at carbon-5, carbon-12, or carbon-15, respectively, as well as related polyunsaturated fatty acids like linoleic acid (Yamamoto, 1991).
15-Lipoxygenase was discovered in the rabbit reticulocyte in 1975 and found to directly attack phospholipids and peroxidate mitochondrial lipids (Schewe et al., 1975; Grüllich et al., 2001). Reticulocyte LOX is capable of degrading lipid membranes (Fritsch et al., 1979; Lankin et al., 1985). The reticulocyte LOX, 15-LOX, is a major pathway for organelle degradation in rabbit reticulocytes (Grüllich et al., 2001). In the presence of a LOX inhibitor, endoplasmic reticulum membranes incubated with 15-LOX in vitro were not permeabilized, but in the absence of the inhibitor permeabilization of endoplasmic reticulum membranes occurred (van Leyen et al., 1998).
Mitochondrial degradation in maturing reticulocytes was able to occur in the absence of ETYA (5,8,11,14-eicosatetraynoic acid), a LOX inhibitor, but was delayed in the presence of ETYA, indicating that LOX is largely responsible for the degradation of reticulocyte mitochondria.
Acrosomal exocytosis (AE), which is the exocytosis of soluble acrosome material after the fusion of the outer acrosomal membrane and overlying plasma membrane, is required for fusion of the spermatozoon with the plasma membrane (Lax et al., 1990). 15-LOX induces the acrosome reaction in the presence of Ca2+ (Oliw and Sprecher, 1989; Lax et al., 1990).
Current methods of contraception include surgical sterilization of women and oral contraceptive use by women, which are the most common methods of contraception in the U.S. Hormone modulating contraceptives include combined (estrogen/progestin) contraceptives, such as combined injectable contraceptives, combined oral contraceptives; and progestin-only contraceptives, such as norplant implants, progestin-only injectable contraceptives, or progestin-only pills. However, combined estrogen/progestin oral contraceptives may cause or lead to thromboembolic disorders, cerebrovascular accidents, coronary artery disease, liver abnormalities, estrogen dependent cancers, and pregnancy. Other methods of contraception include intrauterine devices; cervical cap; barrier methods, such as male condoms, female condoms, diaphragms, spermicides, or contraceptive sponge; and rhythm methods, which are highly dependent on the individuals involved. Many of these methods may have far reaching side effects physiologically and otherwise. Thus, there is a need for improved methods of regulating fertility as well as methods for diagnosing fertility for both humans and a variety of animals.